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41、第五篇 Smoking and Cancer Americans smoke six thousands million cigarettes every year (1970 figures). This is roughly the equivalent of 4195 cigarettes a year for every person in the country of 18 years of age or more. It is estimated that 51 % of American men s moke compared with 34 % of American women. Since 1939, numerous scientific studies have been conducted to determine whe ther smoking is a health hazard. The trend of the evidence has been consistent a nd indicates that there is a serious health risk. Research teams have conducted studies that show beyond all reasonable doubt that tobacco smoking, particularly cigarette smoking is associated with a shortened life expectancy. Cigarette smoking is believed by most research workers in this field to be a n important factor in the development of cancer of the lungs and cancer of the t hroat. Male cigarette smokers have a higher death rate from heart disease than O n-smoking males. Female smokers are thought to be less affected because they do not breathe in the smoke so deeply. The majority of physicians and researchers consider these relationships proved to their satisfaction and say, ’Give up smoking! If you don’t smoke, don’t start! ’ . It might be helpful to look at what tobacco-smoking actually does to the hum an body. Smoke is a mixture of gases, vaporized chemicals, minute particles of a sh, and other solids. There is also nicotine, which is a powerful poison, and bl ack tar. As the smoke is breathed in, all these components form deposits on the membranes of the lungs. One point of concentration of deposits is where the air tube divides. Most lung cancer begins at this point. Smoking also affects the heart and blood vessels. It is known to be related to Beurger’s disease, a narrowing of the small veins in the hands and feet that can cause great pain. Smokers also die much more often from heart disease. While all tobacco-smoking affects life expectancy and health, cigarette smok ing appears to have a much greater effect than cigar or pipe smoking. However, n icotine consumption is not diminished by the latter forms, and current research indicates a causal relationship between all forms of smoking and cancer of the m outh and throat. Filters and low tar tobacco are claimed to make smoking to some extent safer, but they can only marginally reduce, not eliminate the hazards.Which of the following statements is NOT true according to the info rmation given in the passage? ____
A.Tobacco smoking can cause life-shortening diseases.
B.There are twice as many men smokers as women smokers in the U. S. According to the 1970 figures.
C.Filters can only decrease rather than eliminate the harm to the human body.
D.In the smoke there is nicotine which is an important factor in the development of cancer of some organs.
42、(同41题)The statement "be associated with a shortened life expectancy" in the s***nd aragraph signifies____
A.\!cause a life expectancy to shorten".
B.\!be caused by a shortened life expectancy".
C.\!will change with the shortened life expectancy".
D.\!will cause from the shortened life expectancy".
43、(同41题)Female smokers are probably less affected by heart disease because____
A.cigarettes women smoke are treated in a special way.
B.tissue of the heart can get rid of the poisonous elements.
C.they inhale the smoke less deeply.
D.they, in most cases, pretend to be smokers.
44、(同41题)Tobacco smoke is a mixture____
A.of two poisonous elements.
B.of various poisonous substances.
C.of some irritant gases.
D.of carbon dioxide and water vapour.
45、(同41题)Harmfulness from all forms of smoking to the human body may be arranged in severity sequence as follows:____
A.Cigarette smoking is put first, and next comes cigar or pipe smoking.
B.No 1 killer is cigar smoking, and it’s followed by cigarette or pipe smoking.
C.Cigar or pipe smoking has nearly no effect on the human body in contrast with igarette smoking.
D.All forms of smoking are similar in effect harmful to the human body.
46、Vision。 I____。Vision is physiological power of sight. Vision is the faculty by which, th rough the material organ, the eye, the visible external world is perceived. Many simple organisms have light receptors and can thus react to motion and shadows, but true vision involves the formation of images in the brain. Eyes of differen t organisms provide images of varying clarity: This article deals with vision in humans and other animals with eyes of comparable complexity.
47、Basic P____。On ordinary optical principles, a point above the direct line of vision co mes to a focus at a point of the retina below its center, and vice versa. If a r etina were observed by another person, the observer would see that the image of an object is formed on the retina, and that this image is inverted. Any increase in the magnitude of the retinal image is generally associated with approach of the object; if this same result is brought about by means of lenses, however-eve n where the real distance is increased-the object still seems to approach. This seeming approach is the result of an unconscious process of reasoning. The mind interprets any given object as being of a known or ascertained size.
48、Sight D____。The most common disturbance to vision is caused by crystals or other small opaque bodies in the humors of the eye, which are usually only a passing inconv enience. Much more serious are opacities called cataracts, which develop in the lens as a result of mechanical injury, advancing age, or dietary deficiencies. O pacity of the cornea also causes obscured vision, but this condition may be repa ired through transplantation of a section of clear cornea from another person.
49、W____of Vision。Day blindness, or hemeralopia, is caused by incipient clouding or opacity of one or more of the ocular tissues. Night blindness, or nyctalopia, results fr om a deficiency of visual purple in the retina caused by lack of vitamin A. Colo r blindness is attributable to a congenital defect in the retina or other nerve portions of the optic tract. Amblyopia is weakness of vision without apparent st ructural damage of the eye and may be caused by poisoning by drugs, alcohol, or tobacco or may be associated with hysteria or uremia.
50、B ____。Pressure on the optic nerve may cause blindness in the right or left halve s of both eyes or in the inner or outer halves of both eyes. Detachment of the r etina from the interior of the eyeball causes blindness by allowing the retina t o drift to the bottom of the eye out of range of the image formed by the lens; p ermanent correction usually requires surgery. Introduction Principles Defects Weakness Blindness
51、Environmental Impacts of Energy Production All primary energy sources that are ***nomic will be required if the world is to avoid energy starvation. The world’s needs for e(51)____ energy have been met successively by wood, coal and oil. As these sources decline in importance o(52)____ approach depletion, natural gas, nuclear power, solar and other ’alternative’ energy sources are expected to m(53)____ an increasing fraction of total demand. The production and use of energy can h(54 )____ a significant effect on the environment. The environmental consequences of the use of some energy sources c ould conceivably b***me so great t(55)____they could limit growth in energy con sumption. On the other hand, meeting energy needs for ***nomic development and s(56)____well-being may require that some environmental impcts be accepted. Environmental impact assessments are being used increasingly I(57)____ dec ision-making by national authorities r(58)____ for selecting appropriate energy options or energy mixes. The impacts of energy production may be of short durati on, long lasting, or irreversible. They may be of l(59)____or global concern, and may involve trans-boundary issues of international significance; they may af fect different communities, p(60)____ groups and countries in different ways. Th ey may be detrimental or beneficial. The nuclear industry has taken a leading ro le in addressing systematically both short- and long-term issues.
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答案：
1 D 2 B 3 A 4 B 5 B 6 D 7 B 8 D 9 C 10 C 11 A 12 C 13 A 14 D
15 C 16 C 17 C 18 A 19 B 20 B 21 C 22 A 23 C 24 B 25 A 26 D 27 C 28 D 29 B 30 A 31 C 32 C 33 B 34 B 35 C 36 B 37 C 38 A 39 D 40 B 41 B 42 A 43 C 44 B 45 A 46 Introuction 47 Principles 48 Defects 49 Weakness
50 Blindness 51 energy 52 or 53 meet 54 have 55 that 56 social 57 in 58 responsible
59 local 60 population
